Pneumatic sheet stacking mechanism



Feb. 4, 1964 A. FUX 3,120,384

PNEUMATIC SHEET STACKING MECHANISM Filed Sept. 21, 1960 3 Sheets-Sheet 1 IN V EN TOR.

\ AIME FUX ATTORNEY Feb. 4, 1964 A. FUX 3,120,384

PNEUMATIC SHEET STACKING MECHANISM Filed Sept. 21, 1960 3 Sheets-Sheet 2 INVENTOR. AIME FUX ATTORNEY Feb. 4, 1964 A. FUX

PNEUMATIC SHEET STACKING MECHANISM 3 Sheets-Sheet 3 Filed Sept. 21, 1960 IN V EN TOR.

AIME FUX ATTORNEY United States Patent ()filice 3,129,384 Patented Feb. 4, 1964 3,120,384 PNEUMATIC HEET STACIGNG MECHANESM Aime Fux, Philadelphia, Pa, assignor to Burroughs Corporation, Detroit, Mich, a corporation of Michigan Filed Sept. 21, 1966, Ser. No. 57,418 16) Claims. ll. 271-68) This invention relates generally to sheet feeding machines and more particularly to a high speed mechanism for stacking sheets individually in succession in pile or stack formation.

An object of the invention is to provide a mechanism for sheet feeding and the like machines which will stack sheets at high speed in a receptacle or stacking bin without the danger of mutilating the leading edge of the sheets ordinarily encountered in high speed stacking.

Another object of the invention is to provide a high speed stacking mechanism for stacking sheets in succession and with means to assure that the sequence or order of the sheets will be preserved.

Another object of the invention is to provide such a mechanism in which an incoming successive sheet delivered into a stacking bin or receptacle will not come into sliding contact with a previously delivered sheet in the receptacle, thus to prevent friction between adjacent sheets and to better preserve their condition.

A more specific object of the invention is to provide a stacking mechanism for sheet items and the like wherein the stack height or location of the top or end of a stack of sheets in a stacking receptacle is controlled auto matically by the position of the top or endmost sheet of the stack.

A further object of the invention is to provide a pneumatic control for a stack support or follower which may be utilized in a machine either for stacking sheets against the support or follower or for supplying sheets to be fed from a stack initially placed against such stack support or follower.

In accordance with the above objects and first considcred briefly in its broad aspects, the invention utilizes a pneumatic decelerating mechanism for slowing down sheets delivered rapidly into a stacking bin or receptacle. The decelerating mechanism may be so adjusted, if desired, such that the momentum of the slowed-down sheets will enable them to reach a registration edge in the stack ing bin, however, there is preferably provided, means, regarded as part of the decelerating mechanism, when used, for feeding the slowed-down sheets through a short distance to the registration edge. The stacking mechanism is so arranged that when an incoming sheet reaches a predetermined position in the stacking bin, preferably at the registration edge, the sheet will be rapidly removed from the path of the next incoming sheet and deposited on or against a stack support or stack follower. The stack support or stack follower responds to the incoi ing sheets and moves or adjusts itself automatically under the control of a pneumatic mechanism thereby to maintain the stack height or location of the top or end of the stack of sheets in the receptacle at a predetermined position.

The invention will be more clearly understood when the following detailed description of the preferred embodiment thereof is read in conjunction with the accompanying drawings in which:

FIG. 1 is a plan view of a stacking mechanism constructed in accordance with the invention;

FIG. 2 is an enlarged sectional View taken along line 22 of FIG, 1, illustrating a sheet decelerating mechanism;

FIG. 3 is an enlarged detail of guide means for a stack follower plate;

FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 2;

FIG. 5 shows a plurality of nozzle elements, shown also in FIG. 2, and illustrating the flow of compressed air therefrom directed toward a sheet stack;

FIG. 6 is a sectional View taken along line 66 of FIG. 1; and

FIG. 7 is an enlarged detail of certain elements of a pneumatic control for the stack follower plate.

Turning now to the drawings and more particularly to FIGURE 1 thereof, the illustrated embodiment of the invention comprises a sheet delivery mechanism 10, a sheet stacking receptacle or bin 12, a suction decelerating mechanism 14 for slowing sheets delivered into the stacking receptacle 12 by the sheet delivery mechanism It and a stack follower mechanism 16, most of which is shown in FIG. 6, for positioning the sheets or cards 18 in the stacking receptacle 1?. in stack formation and for maintaining the end sheet of the stack at a predetermined reference position, as will be explained more fully hereinafter. Arranged between the decelerating mechanism 14 and the sheet delivery mechanism it) is a series of blast nozzles 2t) (see also FIGS. 2 and 5) connected to a source of compressed air 21 (FIG. 6) by means of a hose 22.

The sheet delivery mechanism 19 comprises stationary sheet guide members 23 and 24 (FIG. 6) which are spaced apart a distance slightly greater than the thickness of a sheet or card 18 and formed gradually toward their exit region 25 (FIG. 1) to provide a curved or trough-like chute guideway 26 (FIG. 6) therebetween. The sheets or cards 18 are delivered individually through the guideway 26 by means of a power driven roller 23 and a cooperating pressure roller 3% which extend through suitable openings in the guide members 23 and 24.

The decelerating mechanism 14 comprises a stationary suction shoe 32 (FIGS. 2 and 4) and preferably a slowmoving conveyor in the form of a series of endless belts 34 which cooperate with the suction shoe 32 for trans porting each delivered sheet or card 18 at a decelerated rate of speed to a registration surface in the stacking receptacle 12 which, in the present embodiment, takes the form of power driven slow moving rollers 36 (FIGS. 1 and 2), preferably faced with a resilient material such as rubber.

The suction shoe a2 is provided in its sheet or card engaging face 38 (FIG. 4) with a plurality of spaced apart elongated slots d for slidably guiding the belts 34, the face 33 being curved transversely to substantially correspond with the curvature of the guideway 26 at the exit thereof. The belts 34 cooperate with inner surfaces 42 of the suction shoe 32 to form elongated shallow suction spaces or grooves 44 which terminate at their ends 44a and 44b (FIG. 2) where the surfaces 42 run out to the face 3%. Each of the spaces or grooves 44 communicates with one of a plurality of minute passages or ports as opening at its inner end into a cavity 48 in communication with a source of vacuum such as a pump 49 (FIG. 6) by means of a hose 5%. The belts 34 pass around idler pulleys 52, 53 and 54 (FIG. 1) and a power driven roller 55.

The stack follower mechanism 16 comprises a follower plate 56 secured to a bearing 53 slidably and rockably mounted on a fixed guide shaft 59. The bearing 58 is journalled at one end 69 (FIG. 3) in a guide fitting 61 provided with a roller 62 arranged to ride in a fixed way 63. A lug 61a on the guide fitting 61 is in the path of movement of an offset 58a of a stop member 58b secured to the bearing 58 to limit downward movement of the follower plate 56 whenever it is rocked or lowered.

into the stacking receptacle 12.

A cable 64 (FIG. 6) is secured at one end to the guide O fitting 61, passes about an idler pulley 65 and is secured at its opposite end to the top of a gravity responsive weight or piston 66 slidably mounted in a vertical cylinder 63. A second cable 70 is similarly connected at one end to the guide fitting 61, passes about idler pulleys 72, 73 and 74 and has its opposite end connected to the bottom of the piston 66. A hose 76 leading from a source of vacuum, such as a pump 7 S, communicates with the cylinder 68 above the piston 66, and a hose 80 leading from the vacuum pump 78 communicates with an inlet opening 82 (FIG. 7) in a side wall 84 of the stacking receptacle 12.

The various members of the stack follower mechanism 16 are suitably chosen with respect to weight, vacuum pressure, friction, etc. such that the piston 66 tends to drop and move the stack follower plate 56 toward the decelerating mechanism 14 but is controlled in so doing by the size of the inlet opening 82. 1f the inlet opening 82 is closed sufficiently, the vacuum pump 7 8 will reduce the pressure above the piston 66 to such an extent that the piston will rise and move the follower plate 56 away from the decelerating mechanism 14. On the other hand, if the inlet opening 62 is sufficiently open, the pump 78 will then draw sufficient air through the inlet opening 82 so that the reduced pressure above the piston 66 will not be sufiicient to overcome the tendency of the piston to drop and the piston will therefore move the follower plate 56 toward the decelerating mechanism 14.

In the operation of stacking cards, a card 13 is delivered into the guideway 26 between the curved plates 23 and 24 by associated feed rollers 86 and 83 (FIG. 1) and fed into the stacking receptacle 12 by the delivery rollers 28 and 3t). Compressed air is supplied continuously by the source 21 to the nozzles 20 but is ineffective to defiect the leading portion of the card 18 out of the path of feeding so long as a portion of the card is still in the guideway 26. The resistance of the card to deflection is obtained by the curved or trough-like formation imparted to the card by the curved guideway 26 which gives it stiffness and rigidity. Suction is applied continuously by the pump 49 through the hose 50 to maintain the cavity 48 (FIG. 4) at a reduced pressure. The incoming card passes across the curved face 38 of the suction shoe 32 until its leading edge reaches the position 4411 (FIG. 2) where the grooves 44 terminate or run out at the face 38. At this time the card has substantially sealed the grooves 44 and is under the decelerating effect of the suction applied to these grooves through the ports 46, cavity 48 and hose 50. When the card has substantially sealed the grooves 44, as just described, it trailing edge will have left the nip of the delivery rollers 28 and 30, but will still be in the guideway 26, and the card will then be under the control of the suction through the shoe 32 and the cooperating continuously rotating slow moving belts 34. The b'elts 34 transport the card the remaining short distance into the stacking bin 12 until its leading edge registers against the resilient surface or rotating rollers 36, at which time the trailing portion of the card has left the guideway 26 and is free to be acted upon effectively by the compressed air issuing from the nozzles 20. Because of the curved, rigid formation of the card at this time, the air issuing from the nozzles 20 will not bend the trailing portion of the card away from the leading portion but will blow the entire card away from the suction shoe 32 and belts 34 and stack it against the follower plate 56.

As the cards 18 are stacked in succession against the follower plate 56, the follower plate will be adjusted auto matically to maintain the end of the stack of cards at a predetermined equilibrium or reference position 96 (FIG. 7). This occurs as each card gradually closes the inlet opening 82 to diminish the suction applied therethrough by the pump 7 8 and to cause a corresponding increase in suction by the pump 78 on the top of the piston 66 so that the piston will rise a corresponding distance and move the follower plate 56 in the direction away from the decelerating mechanism 14 until the end card of the stack reaches the equilibrium or reference position 90.

In order to assure that an incoming succeeding card will not interfere with the trailing portion of a previous card being stacked by the compressed air issuing out of the nozzles 20, and to assure further that succeeding adjacent cards will not slide one upon the other, the follower plate 56 is preferably inclined to the face 38 of the suction shoe 32 to provide a tapered or funnel-shaped entrance region 92 (FIG. 1) for incoming cards. Also, the resilient surfaces or rollers 36 are preferably rotated, and continuously, to maintain the leading portion of the cards firmly against the stack and out of the way of incoming cards.

As described earlier, the decelerating mechanism 14 preferably includes the suction shoe 32 and the slow moving belts 34, however, in certain stacking operations it may be advantageous to omit the belts 34. In such case, the decelerating mechanism would be constituted by the suction shoe alone together with its source of vacuum and hose connection and the suction therethrough suitably regulated to enable the momentum of the sheets or cards to carry them the full distance into the stacking receptacle.

While there has been shown a specific structure exemplary of the principles of the invention, it is to be understood that this is but one embodiment thereof and that the invention may be constructed in a variety of shapes, sizes and modifications Without departing from the true spirit and scope thereof. Accordingly, it is to be understood that the invention is not to be limited by the specific structure disclosed but only by the subjoined claims.

What is claimed is:

1. In a pneumatic sheet stacking mechanism, a stacking bin, a chute, for guiding sheets into said stacking bin and imparting to each sheet a curved formation transverse to the direction of feeding through the chute, means for feeding sheets in succession through said chute into said stacking bin, suction mechanism acting on the leading major portion of the sheets for substantially contacting and decelerating each sheet fed through said chute into said stacking bin and for preserving said curved formation of the decelerated sheet, compressed air means for removing said decelerated sheet from said suction mechanism by overcoming the force of suction thereof as the trailing edge of the decelerated sheet leaves said chute and for removing the decelerated sheet from the path of a succeeding sheet to be fed through said chute, a movable stack follower for positioning said sheets in the stacking bin in stack formation, and pneumatic means for controlling the movement of said stack follower to maintain the end sheet of a stack of sheets in said stacking bin at a predetermined location therein.

2. In a pneumatic stacking mechanism for flexible sheet items, a stacking bin, a chute for guiding such items individually into said stacking bin and imparting to each item a trough-like formation in the direction of feeding through the chute, means for feeding said items in succession through said chute into said stacking bin, suction mechanism acting on the leading major portion of the items for substantially contacting and decelerating each said item fed through said chute into said stacking bin and for preserving said trough-like formation of the decelerated item, compressed air means for blowing said decelerated item away from said suction mechanism while it is under the influence thereof as the trailing d of the decelerated item leaves said chute and for removing the decelerated item from the path of a succeeding item to be fed through said chute, a movable stack follower for positioning said items in the stacking bin in stack formation, and pneumatic means for controlling the movement of said stack follower to maintain the end item of a stack of said items in said stacking bin at a predetermined location therein,

3. in a pneumatic mechanism for stacking sheets, cards and the like, a stacking bin, means for conveying cards one at a time to said stacking bin in a given direction, means for delivering said conveyed cards in the same uninterrupted direction one at a into said stacking bin, suction mechanism having a predetermined force and arranged to operate on the leading major portion of one side of a said card in the direction of delivery into said stacking bin for gripping and decelerating the delivered card, and compressed air means having a greater force than said suction mechanism and operative upon the trailing portion of the decelerated card upon the same side thereof as said suction mechanism for removing said decelerated card from the grip of said suction mechanism, by overcoming the force of suction, and out of the path of an incoming succeeding card to be delivered into said stacking bin.

4-. In a pneumatic mechanism for stacking sheets, cards and the like, a stacking bin, means for delivering said cards one at a time into said stacking bin, a stationary suction device arranged to operate on the ieadin major portion of said card in the direction of delivery into said stacking bin for decelerating the delivered card before it is fully delivered into said stacking bin, slow moving belt means cooperating with said suction device for conveying said decelerated card and the remainder of the distance into said stacking bin, and compressed air means operative upon the trailing portion of the decelerated card for removing said decelerated card from the influence of said suction device and belt means, by overcoming the force of suction, and out of the path of a succeeding card to be delivered into said stacking bin.

5. in a pneumatic sheet stacking mechanism the combination comprising, means forming a curved guideway for forming a sheet into a trough-like formation to stiffen the sheet longitudinally, means for feeding a sheet through said curved guideway into a stacking receptacle, and a suction shoe for decelerating a said sheet fed into said stacking receptacle, said suction shoe having a curved sheet engaging surface substantially corresponding in curvature to said curved guideway to preserve the trough-like formation and stififness of the sheet until it is fully into th receptacle.

6. A combination according to claim 5 and including at least one endless rotating belt cooperating with said suction shoe for conveying a said sheet decelerated thereby to the limit of its travel in said stacking receptacle.

7. in a pneumatic mechanism for stacking flexible sheet-like articles, a stacking bin, means for delivering said articles in succession into said stacking bin in a longitudinally rigid condition, stationary suction mechanism continuously operating and acting on the leading portion of a delivered article on one side thereof for decelerating the said delivered article, stationary compressed air means acting on the trailing portion of a decelerated article on the same side thereof as said suction mechanism and effective when the article is fully into the stacking bin for blowing the decelerated article away from said suction mechanism and out of the path of an incoming succeeding article, and a stack follower mechanism automatically responsive to incoming articles in said stacking bin for maintaining the endmost article of a stack of said articles at a predetermined position in said stacking bin.

8. In a pneumatic mechanism for stacking flexible sheet like articles in succession, a stacking bin, means for delivering an article in a transversely curved and longitudinally rigid formation into said stacking bin, suction mechanism acting on the leading portion of a delivered article on one side thereof for decelerating the said delivered article while in said curved formation and for maintaining the rigidity and curvature thereof, means for directing a stream of compressed air against the trailing portion of a decelerated article against the same side thereof that said suction mechanism is acting upon in such manner that when the article is fully into the stacking bin the air will blow the decelerated article away from said suction mechanism and out of the path of an incoming succeeding article and for stacking the same, and a stack follower mechanism automatically responsive to said incoming stacked articles in said stacking bin for maintaining the endmost article of the stack at a predetermined position in said stacking bin.

9. a pneumatic sheet-stacking mechanism, a sheet receptacle having a movable registration surface, means for delivering sheets in succession into said receptacle in a longitudinally rigid condition, suction mechanism acting on the leading portion of a delivered sheet on one side thereof for decelerating said delivered sheet and for maintaining the rigidity thereof, means for conveying said ecelerated sheet until its leading edge substantially contacts said registration surface, means for directing a stream of air against the trailing portion of a decelerated sheet against the same side thereof that said suction mechanism is acting upon in such manner that when said leading edge is substantially in contact with said registration surface the air will blow the decelerated sheet from the path of an incoming succeeding sheet, astack follower mechanism automatically responsive to incoming sheets in said receptacle for maintaining the endmost sheet of a stack of said sheets at a predetermined position in said receptacle, and means for moving said registration surface in such manner as to urge said leading edges of delivered sheets toward said stack follower mechanism.

10 In a pneumatic sheet stacking mechanism, a sheet eceptacle having a registration surface, means for delivering sheets in succession into said receptacle in a longitudinally rigid condition, stationary suction mechanism acting on the leading major portion of a delivered sheet for decelerating said delivered sheet and for maintaining the rigidity thereof, endless belts cooperating with said suction mechanism for conveying said decelerated sheet until its leading edge substantially contacts said registration surface, means for directing a stream of compressed air against the trailing portion of a decelerated sheet in such manner that when said leading edge is substantially in contact with said registration surface the force of the compressed air will overcome the force of suction of the suction mechanism and will cause the air to blow the sheet away therefrom and out of the path of a succeeding sheet, and a stack follower mechanism automatically responsive to incoming sheets in said receptacle for maintaining the endmost sheet of a stack of said sheets at a predetermined position in said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 730,857 Armand June 16, 1993 1,057,601 White Apr. 1, 1913 1,646,529 Fallot Oct. 25, 1927 2,178,879 Mikes Nov. 7, 1939 2,261,972 Matthews Nov. 11, 1941 2,474,997 Wormser July 5, 1949 2,895,552 Pomper et al July 21, 1959 2,944,813 Smith July 12, 1960 

1. IN A PNEUMATIC SHEET STACKING MECHANISM, A STACKING BIN, A CHUTE, FOR GUIDING SHEETS INTO SAID STACKING BIN AND IMPARTING TO EACH SHEET A CURVED FORMATION TRANSVERSE TO THE DIRECTION OF FEEDING THROUGH THE CHUTE, MEANS FOR FEEDING SHEETS IN SUCCESSION THROUGH SAID CHUTE INTO SAID STACKING BIN, SUCTION MECHANISM ACTING ON THE LEADING MAJOR PORTION OF THE SHEETS FOR SUBSTANTIALLY CONTACTING AND DECELERATING EACH SHEET FED THROUGH SAID CHUTE INTO SAID STACKING BIN AND FOR PRESERVING SAID CURVED FORMATION OF THE DECELERATED SHEET, COMPRESSED AIR MEANS FOR REMOVING SAID DECELERATED SHEET FROM SAID SUCTION MECHANISM BY OVERCOMING THE FORCE OF SUCTION THEREOF AS THE TRAILING EDGE OF THE DECELERATED SHEET LEAVES SAID CHUTE AND FOR REMOVING THE DECELERATED SHEET FROM THE PATH OF 